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> 计算:①y7x÷(-2x)②a-2a-1-2a-3a-1③12m2-9-2m-3④x2x-1-x-1.-数学
计算:①y7x÷(-2x)②a-2a-1-2a-3a-1③12m2-9-2m-3④x2x-1-x-1.-数学
题目简介
计算:①y7x÷(-2x)②a-2a-1-2a-3a-1③12m2-9-2m-3④x2x-1-x-1.-数学
题目详情
计算:
①
y
7x
÷(-
2
x
)
②
a-2
a-1
-
2a-3
a-1
③
12
m
2
-9
-
2
m-3
④
x
2
x-1
-x-1
.
题型:解答题
难度:中档
来源:不详
答案
①
class="stub"y
7x
÷(-
class="stub"2
x
)=
class="stub"y
7x
×(-
class="stub"x
2
)=-
class="stub"y
14
;
②原式=
a-2-(2a-3)
a-1
=
class="stub"a-2-2a+3
a-1
=
class="stub"-a+1
a-1
=
-(a-1)
a-1
=-1;
③原式=
class="stub"12
(m-3)(m+3)
-
2(m+3)
(m-3)(m+3)
=
12-(2m+6)
(m-3)(m+3)
=
class="stub"-2m+6
(m-3)(m+3)
=
-2(m-3)
(m-3)(m+3)
=-
class="stub"2
m+3
;
④原式=
x
2
x-1
-
(x-1)
2
x-1
=
x
2
-(
x
2
-2x+1)
x-1
=
x
2
-
x
2
+2x-1
x-1
=
class="stub"2x-1
x-1
.
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题目简介
计算:①y7x÷(-2x)②a-2a-1-2a-3a-1③12m2-9-2m-3④x2x-1-x-1.-数学
题目详情
①
②
③
④
答案
②原式=
③原式=
④原式=